http://www.slas.us/gallery2/main.php?g2_itemId=4360 - Clear Skies Kurt On June 5, 2011, the Dawn solar system explorer spacecraft was about 385,000 kilometers (0.0025 a.u.) from its planned July rendezvous with the 530 kilometer diameter asteroid Vesta, and the spacecraft was approaching its destination at about 725 kilometers per hour (450 miles per hour). Both objects are about 230 million kilometers (1.53 a.u.) from Earth. Dawn will vastly improve our best image of Vesta, taken by Hubble in 1997, shown in left inset. The Dawn spacecraft (shown in the right inset) is powered by a revolutionary ion particle drive, and after orbiting Vesta, the spacecraft will break orbit and accelerate to a February 2015 encounter with dwarf planet Ceres. The position of Dawn on June 5, marked with the "X" was approximated by scaling a computer generated planetarium chart from the NASA JPL Solar System Live online applet. The image is approximately 3 degrees wide and approximates the view of magnitude 5.9 Vesta and magnitude 4.2 iota Capricorn as seen in the predawn southeast sky through 10x50 binoculars. iot Capricorn can easily be found using any planisphere. Related information: Jet Propulsion Laboratory, Where is Dawn Now? (Webpage). http://dawn.jpl.nasa.gov/mission/live_shots.asp Marc Rayman, JPL Engineer, Dawn Journal (Blog) (May 27, 2011). http://dawn.jpl.nasa.gov/mission/journal_05_27_11.asp JPL, Ion Propulsion. (Webpage). http://dawn.jpl.nasa.gov/mission/ion_prop.asp Rayman, M. Dawn, A mission in development for exploration of main belt asteriods Vesta and Ceres, Acta Astr. 58:605-616 (2006). NASA-JPL Solar System Simulator, online applet http://space.jpl.nasa.gov/ Image Credits: Base Image: K. Fisher (fisherka@csolutions.net). 6-5-2011 10:56UT. Canon Digital Rebel, 800 ISO, 10 sec., f5.6, 50-300mm zoom lens, tripod mounted Vesta Inset: Ben Zellner (Georgia Southern University), Peter Thomas (Cornell University) and NASA, Vesta, Press Release Release Number: STScI-1997-27 (Sept. 1997) http://hubblesite.org/newscenter/archive/releases/1997/27/image/d/ Dawn Spacecraft Inset: NASA, JPL-Caltech, UCLA, McREL. Dawn Spacecraft Illustration. http://dawn.jpl.nasa.gov/multimedia/images/anim_spcecrft_300.jpg